Looper throw out for sewing machines



July 26, 1960 H. HACKLANDER LOOPER THROW our FOR sswmc MACHINES Filed March 25, 1957 IN VEN TOR. Hans Hack/under United States Patent 2,94a301 Patented July 26, 19

LOGPER THROW OUT FOR SEWING MACHINES Hans Hacklander, Warren Township, N.J. assignor to The Singer Manufacturing Company, Elizabeth, N.J., a corporation of New Jersey Filed Mar. 25, 1957, Ser. No. 648,052

8 Claims. (Cl. 112-200) The present invention relates to sewing machines and has for a primary object to provide a new and improved looper throw out for sewing machines. More particularly it is an object of this invention to provide a looper throw out that is particularly adapted for high speed operation of the sewing machine in that the movable member carrying the looper is securely fastened to the looper bar during operation of the machine by a rugged and dependable means designed to withstand the forces involved and which, at the same time, is relatively simple to operate to release the movable looper carrying member from the looper bar for movement to a position in which the looper can be conveniently threaded. It is also an object of this invention to provide such a mechanism that is simple and economical.

Having in mind the above and other objects that will be evident from an understanding of this disclosure, the invention comprises the devices, combinations and arrangements of parts as illustrated in the presently preferred embodiment of the invention which is hereinafter set forth in such detail as to enable those skilled in the art readily to understand the function, operation, construction and advantages of it when read in conjunction with the accompanying drawings in which:

Fig. l is a horizontal sectional view illustrating the bed of a sewing machine including a looper throw out mechanism constructed in accordance with the present invention, with parts of the machine broken away and with other parts such as the bed cover plate and the looper thread take up omitted more clearly to illustrate the underlying mechanism.

Fig. 2 is a detail view illustrating in elevation the looper throw out mechanism of the machine of Fig. 1.

Fig. 3 is a sectional view taken substantially on the line 3-3 of Fig. 2.

Fig. 4 is a sectional view similar to Fig. 3 but illustrating the mechanism in thrown out position.

The present invention is disclosed as embodied in a sewing machine as disclosed in my prior patent application Serial No. 609,836, filed September 14, 1956, to which reference may be had for a more complete description of the machine. As illustrated in the drawings, this machine has a frame including a bed 1 having a bottom wall 2, and an upstanding front wall 3, rear wall 4, end

.wall 5, an end wall 6 spaced inwardly from the left hand end of the bed 1, and an apertured transverse partition 7. A main shaft 8 is journaled for rotation longitudinally of the bed 1 in the end wall and partition 7 and extends through the end wall 5 to the exterior of the frame to receive a belt pulley (not shown) by means of which power is delivered to the machine.

The looper mechanism of the illustrated machine includes a looper bar 9 mounted for oscillation and endwise sliding in the end wall 6 of the bed and in a lug 10 upstanding from the bottom wall 2 in the space between the end Wall 6 and the left hand end of the bed 1. The end of the looper bar 9 is connected by a universal joint 11 to one end of a link 12 which is connected at its opposite end by means of a universal joint 13 to a skewed crank pin 14 mounted upon a crank plate 15 that is in turn mounted upon the end of a rotary looper drive shaft 16 arranged transversely of the bed 1. The shaft 16 is journaled in a boss 17 extending inwardly from the rear wall 4 and in a lug 18 upstanding from the bottom 2 of the bed. Rotation is imparted to the looper drive shaft 16 by a bevel gear 11 that cooperates with a similar gear 20 on the end of the main shaft 3. Upon rotation of the looper drive shaft 16, endwise reciprocation, which constitutes the loop-seizing and loop-shedding movements of the looper, is imparted to the looper bar 9 by the throw of the crank pin 14 relatively to the axis of the shaft 16, and oscillation, which constitutes the needle avoiding movements of the looper, is imparted to the looper bar 9 by the gyrations of the crank pin 14 due to the fact that the axis of the crank pin 14 is inclined relatively to the axis of the looper drive shaft 16 about which it is moved.

A looper carrier 21 has a pair of spaced apertured arms 22 connected by a cross piece 23, the looper bar 9 passing loosely through the apertures in the arms 22. The illustrated looper carrier 21 is designed to be provided with a pair of loopers 24 having cylindrical shanks 25 that are received in bores 26 in the cross piece 23 and secured therein by set screws 27. A looper clamp 28 is mounted upon the looper bar 9 between the arms 22 of the looper carrier 21 and is secured thereon by a split strap connection including a clamping screw 29. The looper clamp 28 has a stop arm 30 presenting a shoulder or surface against which the rear of the cross piece 23 is engaged when the loopers 24 are in operative position. There is provided a clamping element for releasably securing the looper carrier 21 against the stop arm 30 comprising a screw 31 having a threaded shank 32 that is threaded intothe front of the looper carrier 28 and a substantially circular head 33 that is enlarged so that the flange or shoulder presented by the head 33 will overlie the front of the cross piece 23. A wear plate 34 is secured to the front of the cross piece 23 by screws 35 and is disposed between the head 33 and the front of the cross piece. The oneside of the head 33 is slabbed 013?, as at 36, to form a portion of reduced radius with respect to the axis of the screw, the radius being reduced to an amount that is less than the distance from the axis of the screw to the adjacent point of the cross piece 23 so that the cross piece 23 can freely pass the head 33 when the screw is positioned with the slabbed-oif side 36 adjacent to the cross piece 23.

-In the normal operative position, as illustrated in Figs. 2 and 3, the screw 31 is turned down so that not only is the head 33 turned to a position to overlie the cross piece 23 but is also moved axially to clamp the cross piece 23 between the head 33 of the screw and the stop arm 31, thus positively securing the looper carrier 21 to the looper 28 which is in turn secured to the looper bar 9. To release the looper carrier 21 so that it can be thrown out to a threading position, as illustrated in Fig. 4, the screw 31 is backed off to position the slabbed-off side 36 adjacent to the cross piece 23 of the looper carrier 21. In this position, the flange provided by the screw head 33 does not overlie the cross piece 23 so that the looper carrier 21 is free to be pivoted forwardly away from the stop arm 30. The normal tightened position of the screw 31, as illustrated in Fig. 2, is preferably one half a turn from the released position, which condition can be obtained by adjustment of the wear plate 34 by placing shims between the wear plate 34 and the cross piece 23 or by providing diiferent Wear plates of calibrated thicknesses.

In the illustrated embodiment of the invention, the head 33 of the screw 31 is also used to limit the thrown out position of the looper carrier 21. As seen in Fig. 2, the head 33 of the screw 31 is large enough to overlie the inner edges of the arms 22 of the looper carrier 21. Thus, when the looper carrier 21 is pivoted to thrown out position the edges of the arms 22 will engage the head 33. Since, in some of the positions in the cycle of actuation of the loopers, the thrown out position is limited by the fact that the loopers would hit some of the bed structure such as the boss if the machine were accidentally operated while loopers were thrown out thus breaking the loopers, the normal thrown out position is limited to a conveniently accessible threading position in which the loopers will not engage any structure in any of the positions in the cycle of actuation. At the same time, with the loo-pers 24 moved to their extreme right position as seen in Fig. 1 by turning the machine, the screw 31 can be completely removed to permit the looper carrier 21 to be pivoted all the way forward when complete accessibility is required.

Numerous alterations of the structure herein disclosed will suggest thermselves to those skilled in the art. However, it is to be understood that the present disclosure relates to a preferred embodiment of my invention which is for purposes of illustration only and not to be construed as a limitation of the invention. All such modifications which do not depart from the spirit of the invention are intended to be included within the scope of the appended claims.

Having thus set forth the nature of the invention, what I claim herein is:

1. In a sewing machine having a bed, a looper bar, spaced bearings journaling said looper in said bed for endwise and angular movement, a pair of elements mounted on said looper bar between said spaced bearings and comprising a looper carrier mounted on said looper bar for pivotal movement relatively thereto and a looper clamp secured on said looper bar, a looper, means for releasably mounting said looper on said looper carrier, and means for releasably securing said elements together for locking said looper carrier against pivotal movement relatively to said looper bar comprising a stop surface formed upon a first one of said elements and means for clamping the second one of said elements against said stop surface comp-rising a screw threaded into the first one of said elements and having a head engaging the second one of said elements.

2. In a sewing machine, a looper bar, a pair of elements mountedon said looper bar comprising a looper carrier mounted on said looper bar for pivotal movement relatively thereto and a looper clamp secured on said looper bar, a looper carried by said looper carrier, and means for releasably securing said elements together for locking said looper carrier against pivotal movement relatively to said looper bar comprising a stop surface formed upon a first one of said elements and means for clamping the second one of said elements against said stop surface comprising a screw threaded into the first one of said elements and including a head having a portion thereof of reduced radius with respect to the axis of said screw to overlie the second of said elements when said screw is in one position of angular adjustment to prevent pivotal movement of said looper carrier on said shaft and to be clear of said second element when said screw is in another position of angular adjustment to permit pivotal movement of said looper carrier on said shaft to a threading position.

3. In a sewing machine having a bed, a looper bar, spaced bearings journaling said looper in said bed for endwise and angular movement, a looper carrier mounted on said looper bar between said spaced bearings and for pivotal movement relatively thereto, a looper means for releasably mounting said looper on said looper carrier,

a looper clamp secured on said looper bar adjacent to said looper carrier and presenting a stop shoulder against which said looper carrier is engaged when in operative position, and a clamping screw threaded into said looper clamp and having an enlarged head overlying said looper carrier for clamping said looper carrier against said stop shoulder when said screw is tightened to secure "said looper carrier to said looper clamp and for releasing said looper carrier for pivotal movement away from said stop surface when said screw is backed oif.

4. In a sewing machine, a looper bar, a looper carrier mounted on said looper bar for pivotal movement relatively thereto, a looper carried by said looper carrier, a looper clamp secured on said looper bar and presenting a stop surface against which said looper carrier is engaged when in operative position, and a clamping screw threaded into said looper clamp and including a head having a portion of reduced radius with respect to the axis of said screw, said screw being positioned relatively to said looper carrier with the head disposed to over lie said looper carrier when said screw is in one position of angular adjustment to clamp said looper carrier against said stop surface and to be clear of said looper carrier when said screw is in another position of angular adjustment to permit pivotal movement of said looper carrier away from said stop surface.

5. In a sewing machine, a looper bar, a looper carrier mounted on said looper bar for pivotal movement relatively thereto, a looper carried by said looper carrier, a looper clamp secured on said looper bar and presenting a stop surface against which said looper carrier is engaged when inoperative position, a clamping screw threaded into said looper clamp and including a head having a portion of reduced radius with respect to the axis of said screw, said screw being positioned relatively to said looper carrier with the head disposed to overlie said looper carrier when said screw is in one position of angular adjustment to clamp said looper carrier againstsaid stop surface and to be clear of said looper carrier when said screw is in another position of angular adjustment to permit pivotal movement of said looper carrier away from said stop surface, and a plate removably secured to said looper carrier in position to be engaged by the head of said screw.

6. In a sewing machine, a looper bar, a looper carrier comprising a cross piece and a pair of spaced apertured arms loosely receiving said looper bar for pivotally mounting said looper carrier on said looper bar, a looper mounted on said cross piece, a looper clamp secured on said looper bar between the spaced arms of said looper carrier and presenting a stop shoulder engaging said cross piece when said looper carrier is in operative Position, a clamping screw threaded into said looper clamp and including a substantially circular head having a .slabbed-oif side of reduced diameter with respect to the axis of said screw, said screw being positioned relatively to the looper carrier with said head in the path of travel of an engaged portion of said cross piece and movable out of the path of travel of the engaged portion of said cross piece by angular adjustment of said screw to place said slabbed-oif side adjacent to the engaged portion of the cross piece, whereby said head will overlie the engaged portion of said cross piece to clamp said looper carrier against said stop surface when said screw is turned down and will be clear of the engaged portion of the cross piece to permit pivotal movement of said looper carrier away from said stop surface when said screw is backed off.

7. In a sewing machine, a looper bar, a looper carrier comprising a cross piece and a pair of spaced apertured arms loosely receiving said looper bar for pivotally mounting said looper carrier on said looper bar, a looper mounted on said cross piece, a looper clamp secured on said looper bar between the spaced arms of said looper carrier and presenting a stop shoulder engaging said out of the path of travel of the engaged portion of said cross piece by angular adjustment of said screw to place said slabbed-ofi side adjacent to the engaged portion of the cross piece, whereby said head will overlie the engaged portion of said cross piece to clamp said looper carrier against said stop surface when said screw is turned down and will be clear of the engaged portion of the cross piece to permit pivotal movement of said looper carrier away from said stop surface when said screw is backed off, and a plate removably secured to said looper carrier at the engaged portion thereof.

8. In a sewing machine, a looper bar, a looper carrier comprising a cross piece and a pair of spaced apertured arms loosely receiving said looper bar for pivotally mounting said looper carrier on said looper carrier on said looper bar, a looper mounted on said cross piece, a looper clamp secured on said looper bar between the spaced arms of said looper carrier and presenting a stop shoulder engaging said cross piece when said looper carrier is in operative position, a clamping screw threaded into said looper clamp and including a substantially circular head having a slabbed-off side of reduced diameter with respect to the axis of said screw, said screw being positioned relatively to the looper carrier with said head in the path of travel of an engaged portion of said cross piece and movable out of the path of travel of the engaged portion of said cross piece by angular adjustment of said screw to place said slabbed-otl side adjacent to the engaged portion of the cross piece, whereby said head will overlie the engaged portion of said cross piece to clamp said looper carrier against said stop surface when said screw is backed off, said head being further positioned to engage at least one of said arms when said screw is angularly adjusted to permit pivotal movement of said looper carrier for limiting the .pivotal movement of said looper carrier.

References Cited in the file of this patent UNITED STATES PATENTS 1,137,352 Reisbach Apr. 27, 1915 1,725,294 Onderdonk Aug. 20, 1929 1,912,959 Zeier et al. June 6, 1933 2,172,321 Kucera Sept. 5, 1939 2,237,719 Tiebel Apr. 8, 1941 

